There are currently a number of known methods for fabricating arrays. These include printing techniques such as screen printing or ink jet printing, lithographic techniques whereby the array is etched onto a surface, photolithography, direct electrodeposition (deposition of wires), patterning of carbon nanotube/nanofiber arrays and assembly techniques, for example, wires set in an epoxy resin. However, these known methods have a number of limitations. In particular, they are cumbersome to carry out and it is difficult to accurately define the arrays over a large surface area and on the millimeter to nanometer scale. Thus, the resolution of the arrays produced is often poor due largely to that lack of definition. The inability to accurately place sensor sites on such arrays causes problems as qualitative and quantitative measurement is detrimentally affected. In particular, issues of cost arise with the fabrication of nanoscale arrays as, while they can be made, control over definition and cost remain problems which cannot be easily overcome. Economy of scale is a particular issue.
The fabrication of arrays on the millimeter to nanometer scale, particularly on the micrometer to nanometer scale over large surface areas having improved accuracy of definition would be particularly valuable in the areas of sensing, electrochemistry and catalysis. Electrochemistry is the branch of chemistry that deals with the use of spontaneous chemical reactions to produce electricity, and the use of electricity to bring about non-spontaneous chemical change. In particular, it is the study of aqueous chemical reactions which occur at the interface of an electron conductor such as a metal or a semiconductor (the electrode) and an ionically conducting medium (the electrolyte) and which involve electron transfer between the electrode and the electrolyte or species in solution. Catalysis concerns the creation of a new reaction pathway with a lower activation energy, thereby allowing more reactant molecules to cross the reaction barrier and form reaction products.
In a typical electrochemical detection process it is, in general, preferable to employ an array of smaller electrodes as opposed to a single large electrode. Reasons for this include:                the ability to use smaller sample volumes;        application in both in vivo and in vitro measurement;        low depletion rate of target molecules;        low background charging due to their reduced surface area;        reduced IR drop; and        high current density arising from enhanced mass transport to the electrode surface as a result of convergent diffusion.        
Accurately defined arrays would also be valuable for use in:                the analysis of fluids (e.g. biological: blood, urine, milk and non-biological: waste water streams, beverages);        integration with living, biological systems into lab-on-a-chip devices,        in vitro or in vivo biological sensing such as enzyme-linked assays and the detection of many other biomolecules;        catalysis;        trace metal monitoring in the environment;        corrosion monitoring; and        energy production and storage devices.        
Co-pending PCT application number PCT/2011/000052 also concerns microarray structures. However, the microarrays as described in PCT/2011/00052 simply include a continuous inert base substrate with functionalisable areas isolated by an inert material. The functionalisable areas are not stated to be conductively interconnected and the structures do not include at least one continuous interconnected layer, separate to the base substrate material and inert material, that allows for improved functional and structural flexibility of the microarrays formed.
It is therefore an object of the present invention to provide arrays including isolated but conductively interconnected functionalisable areas and/or methods of forming such arrays. It is a further or alternative object of the present invention to at least provide the public with a useful choice.